1. Field of the Invention
This invention relates generally to write drivers, and more particularly, to a technique for matching both the differential and common mode impedance of a write driver to a line (i.e. flex/interconnect) impedance.
2. Description of the Prior Art
When a write driver in a disk drive system is used to write data into a thin film transducer, a flex/interconnect is commonly used to connect the output of the write driver to the thin film transducer. When writing at high data rates (e.g. 1–2 Gb/s), the mismatch of the differential and common mode impedance between the write driver's output and the flex/interconnect input impedance causes severe signal reflections. These differential and common mode reflections degrade the integrity of the signal written onto the thin film transducer, which in turn limits the data rate of the disk drive system.
In view of the foregoing, it would be desirable and advantageous in the write driver art to provide a technique for matching both the differential and common mode impedance of a write driver to a flex/interconnect impedance to achieve minimal signal reflections and permit very high data rates associated with write operations.